Why do we look up to those we respect, stoop to the level of those we disdain and think warmly about those we love? Why do we hide dirty secrets or wash our hands of worries? Why do we ponder weighty subjects and feel a load lift after we have made a decision? Why do we look back on the past and forward to the future?

Such turns of phrase, invoking a physical reality that stands in for intangible concepts, might seem like linguistic flights of fancy. But a rapidly growing body of research indicates that metaphors joining body and mind reflect a central fact about the way we think: the mind uses the body to make sense of abstract concepts. Thus, seemingly trivial sensations and actions—mimicking a smile or a frown, holding smooth or rough objects, nodding or giving a thumbs-up—can influence high-level psychological processes such as social judgment, language comprehension, visual perception and even reasoning about insubstantial notions such as time.